Telecommunication enterprise networks use various devices such as transfer devices and control devices. Examples of methods for representing a network configuration include a method of depicting devices at particular positions on a map using information about their geographical positions (FIG. 1; see “ITU-T Z. 371” of Nonpatent Document 1). In the following description on prior art techniques and on an embodiment of the present invention, the assumption is made that devices in a network are linked in a connection relationship shown in FIG. 1. The method of depicting devices at particular positions of a map using information about their geographical positions is described on the assumption that a network is composed of: an upper-level service device 161 embodied by, for example, a server; lower-level service devices 101, 102, 103 that are terminal devices in the network; transfer devices 121, 122 that perform data transfer; and a control device 141 that controls operation of the transfer devices 121, 122 and lower-level service devices 101-103. The devices are linked in a connection relationship shown in FIG. 1. This method is advantageous in that it produces displays that allow viewers of the screen to readily understand the positions of each device and the geographical area that the device covers.
Among other methods for representing a network configuration is a method based solely on a logical connection relationship among devices without giving any consideration to their geographical information (see FIG. 2; see “ITU-T Z. 371” of Nonpatent Document 1). In FIG. 2, the symbol □ represents a device, and a line between devices represents a link. Further, as a method stemming from this method, there is a method in which, of devices in a network, devices of a same function and same role are placed on a same level (see FIG. 3). In this method, the levels are defined based on the number of devices (number of hops) that data is required to pass through to reach an uppermost device after leaving a level having network terminal devices (indicated by the broken line in FIG. 3) as the lowermost level, and this series of levels is defined as “rungs”. Further, this method lets a screen display device display all devices and all rungs on a screen with devices of a same function and same role placed in an organized manner on a same level. This method illustrated in FIG. 3 is advantageous in that it produces displays which allow the viewer to more easily comprehend on the screen the function and role of each device and the logical configuration of the network.
The screen display methods in FIGS. 1-3, instead of displaying the whole network, may cut out and display only a portion of the network. For how to cut out a portion, mention may be made of cutting out only the configuration of a part of devices and their vicinity, only the configuration of devices in a given area, only a group of devices or rungs having a particular function, or rungs related to a particular service (see Nonpatent Document 2, FIGS. 4 and 5). As an example of cutting out a group of devices having a particular function, mention may be made of cutting out only rungs for a group of devices having a particular control-system function (a control plane). FIG. 4A illustrates connections among the rungs in the network of FIG. 3. FIG. 4B is after the control plane is cut out of the network representation of FIG. 4A. Of the devices in FIG. 4A, FIG. 4B shows only those that are cut out, namely, the control device 141 and the service devices (the upper-level service device 161 and the lower-level service devices 101-103), excluding the transfer devices 121, 122. Note that physically there are transfer devices and transfer links in-between the devices belonging to the control plane. In the display method of FIG. 4B, in order to make it easy to see how the control-system devices are mutually connected, the physical connections with the transfer devices 121, 122 and transfer links between devices are abstracted and represented by control links (in FIG. 4B, represented by the straight broken line). This allows the viewer to more easily understand how the control-system function is effected between devices, on the screen.
As an example of cutting out only rungs related to a particular service, mention may be made of cutting out only rungs of a service plane. FIG. 5A illustrates connections among the rungs in the network of FIG. 3. FIG. 5B is after the service plane is cut out of the network representation shown in FIG. 5A. Of the devices in FIG. 5A, FIG. 5B shows only those that are cut out, namely, the service devices (the upper-level service device 161 and the lower-level service devices 101-103). Note that there are the transfer devices 121, 122 and transfer links in-between these devices and that the transfer devices 121, 122 and the control device 141 belonging to the service plane operate in cooperation to realize the service. In this display method, however, the configurations of the transfer devices 121, 122 and the control device 141 in-between the service-system devices are abstracted and represented by service links 152. This allows the viewer to more easily understand how the service is offered between devices, on the screen.
In a network obstruction (abnormality), it is required: to check whether devices on each rung operate normally; to identify a device that has caused the obstruction; to check whether the abnormality of a given device has caused any impact on other devices; and to grasp the area and number of users affected by the obstruction (hereinafter referred to all together as the extent of obstruction).
Under these circumstances, methods are proposed to clearly indicate to the viewer a relevant area in cases where an alarm of any sort is issued from a device, a link, etc., in a network or where an abnormality is suspected because of absence of response from a device, by superimposing additional marks onto the devices or links or changing the color thereof on the display screen, as illustrated in FIG. 6.